Frank



(No Mode.)

1:". M. STEVENS.

VALVE OPERATING MEGHANISM.

No. 3Z3,'606 Patented Augi 4., 1885.

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WITNESSES: l NVENTOR:

WA@ mi) W2- M N. PETERS, Fholellhvgrzpbr, Walhington. D, C.

NITED STATES PATENT Orricn.

FRANK. M. STEVENS, OF NEV YORK, N. Y., ASSIGNOR TO TIIE STEVENSLOCOMOTIVE AND MACHINE COMPANY.

VALVE-OPERATING MECHANISM.

SPECIFICATION forming part of Letters Patent. No. 323,606, dated August4, 1885.

(No model.)

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splined thereon. By sliding clutch E along Be it known that I, FRANK. M.STEVENS, a said `shaft the segment D is caused to shift the citizenofthe United States, and a resident of the city, county, and State ol'New York,have invented certain new and useful Improvements inValve-Operating liIeclianisnis,of which the following is aspcoiiication.

My invention relates to means for operating a valvemfhereby its regularreciprocating motion may be accelerated and retarded, and whereby thevalve-operating eccentric may be shifted to vary the cut-off or reversethe engine. The novel fea-tures of the invention will be fullyhereinafter described and defined in the claims.

In the drawings, which serve to illustrate my invention, Figure I is asectional side elevation on line l I in Fig. 2. Fig. 2 is a plan with apart of the expansion-guide broken away. Fig. 3 is a sectional elevationon lines 3 3 in Figs. l and 2. Fig. 4 is a transverse section on line etIt in Figs. l and Fig. 5 is a sectional elevation on line 5 5 in Fig. 2.Fig. 6 is a detached view of what I call the multi plying-lever and itsoperating-eccentric. Fig. 7 is a detached side view of thecarrier-block, and Fig. 8 a detached View of the disk link or die. Fig.S illustrates a modification that will be described.

Referring now to the first eight figures, A is the shaft driven by theengine. Itmay or may not be the main shaft.

B is an eccentric mounted on this shaft,the shaft passing looselythrough a slot or slotted aperture therein. The eccentric is embraced bytivo keeper-disks, C C, xed on the shaft, and it bears on its oppositefaces ribs a a, which engage corresponding grooves in the inner faces ofsaid disks C, whereby the eccentric is compelled to rotate ivithsaiddisks and the shaft-,but is free to move at right angles to the axis ofthe shaft, so as to vary the throw or reverse the engine. On one face ofthe eccentric is a rack, b, (seen best in Fig. 3,) and opposite saidrack is aslot in one ofthe disks C, and extending through-this slot soas to en* gage said rack I) is a toothed segment, D, which is fulcrnmedat c on a stud fixed to the shaft A. Coupled to an arm on segment D at dis a link, e, which is coupled at its other end to a clutch, E, whichslides on thc shaft A, being eccentric on the shaft and vary itsposition and throw'. This may be ettectcd While the shaft A isrevolving, and through the medium of a clutch-fork, F, which engages agroove in clutch, as shown 4in Fig.

I Will now describe the means employed for accelerating and retardingthe reciprocating movement imparted to the valve by eccentrics B.

G is the eccentric-rod, the strap G of which embraces eccentric B.

II is what I call the expansion-guide, which I usually bolt to theengine-frame,(not showin) but which may be secured to any part and inany Way so long as it is immovable. In this guide is mounted to play inkeepers a carrienblock, I, to which is coupled the eccentric-rod G. Thusthe eccentric B imparts by its rotation areciprocatory motion to theblock I. The method of connecting the rod G tothe block I will bedescribed hereinafter.

In the block I is mounted a shaft, J, and on the outer or projecting endof this shaft is fulcriiined loosely what I call a multiplyinglever, M,in the lower end of which is mounted a sliding block, N in which turnsan eccentric, O, fixed on a shaft, l?, mounted roA tatively in block I.

On the inner end of shaft ILthat is, inside ol' the expansion-guide Hislined a pinion,

- to any form of valve capable of being recipro` cated as alocoinotiveslide-valve. This valve I have not considered it necessary to show.

It will be seen that when the block I is reciprocated through the mediumof eccentric B the lever M is carried along with it, thereby imparting areciprocating motion to the valve; but this reciprocating motion ismodified-that is, either accelerated or retardedby the vibration of saidlever, which is effccted by the eccentric O, the gear-Wheels, and thefixed rack T. The character of these modifications will be governed bythe distance IOO through which theV block I travels and the respectivesizes of the gear-wheels. I have shown the intermediate R as much longerthan the pinion Q; but the relative sizes of the gear-wheels may bevaried to suit the circumstances of the case.

It will be obvious that the lever M has but one function-namely, tomultiply or magnify the mot-ion imparted by the eccentric O. The use ofthis lever enables me -to employ a smaller eccentric than I otherwisecould, and to operate when the axis of the valve stem is considerablyabove or below the horizontal plane in which the axis of the eccentricplays. ThiSleVer, however, performs, otherwise, only the ordinaryfunctions of an eccentric yoke and rod to connect the eccentric to thevalvestem, and thus impart to the valve the reciprocating motion due torotation of the eccentric, as in all eccentric mechanisms for convertingrotary into reciprocating motion. It is obvious, also, that if theeccentric O be given the proper throw it may be coupled to thevalve-stein by the usual connection.

The shaft Jmay be fixed in the block I, and the link-disk K and gears RS may rotate on it; or it may be rotative and the gears R S be fixed onit; or the disk K and lever M may be mounted on a stud projecting` fromblock I outwardly, and the gears R S -be mounted on another studprojecting inwardly from block I. I employ the construction shown forconvenience only.

I will now describe the mode of connecting the eccentric-rod G to thecarrier-block I.

It will be obvious that when the eccentric B is rotating, the stem G isconstantly shifting from aposition parallel with the line of movementot' block I to an angular position therewith; and it will also beobvious that when the eccentric is shifted at either end of its stroke,in order to vary its thrw or reverse the engine, the same shifting ofthe rod G will occur. Now, if the rod was coupled directly to block I-asby a wrist or pinthere would be a slight reciprocating movement of saidblock I independent of the regular reciprocation of said block by theeccentric, and due to this change of angle of the eccentric -rod. Thisindependent movement would be such as to accelerate the movement Vofsaid block at certain times, thus destroying its regularity. To avoidthis I employ by preference a die, K, which is circular or disklike, andwhich fits snugly but rotatively in an eye in the end G of rod G. Thisdie is sary compensation to preventv any reciprocation of block I otherthan that due to the rotation of the eccentric or the shifting of theeccentric at other points than at the ends of its stroke. This mechanismperforms the same function as a'link if one end of it was coupled toshaft J and the other to rod G at a point corresponding to the center ofdie K. I employ the die in order to get a firm extended bearing. In lieuof this die I might employ the modification illustrated in Fig. S Inthis construction the end G of rod G is provided with a curved slot, K,which is engaged by the shaft J. The radius of this slot is governed bythe amount oflongitudinal movement of rod (I, due to the maximum angleit makes with the line of travel of block I when the eccentric is set atits maximum throw. The effeet of this device is to permit the rod G tovibrate on its fulcrum Il without said vibration disturbing block I.

In order to keep the die K in place, I provide a washer, K, mountedconcentrically on shaft J, so as to lap over the die K, and I prefer tomake this washer in one with said die. They might, however, be separate.I also allow the washer on the fulcrum-pin L to extend over the edgeofthe die K for the same reason. These washers form a lateral bearing forthe die on the outside, and the lever K forms a lateral bearing for iton the inside.

I wish it understood that I may employ my means for modifying thereciprocating motion of the valve with any means for producing vthereciprocating motion; but I prefer the means shown; and I do not limitmyself to a train of gear-wheels such as I have shown. For example, therack T may, in some instances, be arranged to mesh directly with thepinion Q, and the other wheels be omitted,and the rack T need not,necessarily, be mounted on or in the guide H. The disk or plate K',being merely a washer, maybe made separate from K, or even omitted, ifother means are provided for keeping K in place. The ribs a a might alsobe on keepers C, and engage grooves in the eccentric B.

I do not claim herein every means for modifying the reciprocating motionof a valve, as other means have been proposed for accomplishing this nordo I limit myself to the pre` cise construction herein shown, as I mayemploy any equivalent thereof.

Having thus described my invention, I claim- Y 1. In a valve-operatingmechanism, amechanism for modifying the motion of the valve comprising acarrying-block adapted to be reciprocated by the engine, an eccentricmounted rotatively on said carrying-block, a rackand-pinion device,substantially as described, whereby the reciprocating motion of thecarrying-block imparts rotary motion to the eccentric mounted on thecarrying-block, and a connection between the said eccentric and thevalve-stem, whereby the reciprocating motion imparted to the valve bythe reciprocation of ICO IIO

the carrying-block is modified by the rotation of the eccentric,substantially as set forth.

2. In a valve-operating mechanism, a mechanism for modifying thereciprocating motion of the valve comprising a carrying block adapted tobe reeiprocated by the engine, an eccentric mounted rotatively on saidcarrying-block, a rack-and-pinion device, substantially as described,for converting reciprocating motion of the carryingbloek into rotarymotion of said eccentric, and alever fulcrumed on said carrying-blockand constructed to connect the said eccentric to the valve-stem, wherebythe motion imparted by said eccentric is magnified or multiplied,substantially as shown and described.

3. In a valve operating mechanism, the combination of a valve-operatingeccentric, its strap, its rod G, `fnlcrumed-at L on the carryingbloek,the said carrying-block arranged to reciprocate, as shown, and themechanism, substantially as described, for coupling said rod G to thecarrying-block, whereby the effeet of the vibration of the said rod onsaid block is neutralized, substantially asset forth.

4. The combination, with the main shaft A, ofthe keepers C C, ixedthereon and provided with grooves to receive ribs on the eccentric, theslotted eccentric B, provided with ribs a c, and arack, b, thesegment-rack D, pivoted at e on the shaft and arranged to mesh with rackb through a slot in one oi' the keepers C, the clutch or sleeve E,splined on the shaft and constructed to receive a fork, F, the said forkF mounted to slide, as shown, and the link e, connected at one end torack D at d, and at the other end to clutch E, Wherebyreciprooation ofsaid sleeve rotates rack D, substantially as shown and described.

5. The mechanism for modifying the reciprocating motion of the valvecomprising the carrying-block arranged to play in guides, theoscillating lever M, the eccentric O, and its shaft, the fixed rack T,and the gear-wheel or Wheels, whereby rotation is imparted to eccentricO O, all arranged to operate substantially as set forth.

6. The combination, with the eccentric B and its rod, of thefulcrum-stud L, the linkdisk K, the stud or shaft J, and thecarry-ingblock i, said block being mounted in guides, and all arrangedto operate substantially as set forth.

7. The combination of the shaft A, the valveoperating eccentric and itsslotted rod, the fulerum-pin L, the link-disk K, the guide H, thecarrying-block I, the stud or shaft J, the lever M, fulcrumed on J, theeccentric O and its sliding block and shaft, the fixed rack T, and thegeai'\vl1ee1s Q, R, and S, all arranged to operate substantially as setforth.

In Witness whereof I have hereunto signed my name in the presence of twosubscribing Witnesses.

FRANK. M. STEVENS.

Witnesses:

FRED A. CAsEY, J. E, DEWEY.

